Children with severe temper outbursts (STO) represent a highly impaired and heterogeneous group. They often receive multiple psychiatric diagnoses, which suggests that our current diagnostic system is unable to adequately capture their symptoms of emotional and behavioral dysregulation. In addition, little is known about the adolescent outcomes of children who exhibit STO. The primary aims of the PI's R15 AREA grant are to (1) examine psychopathology, and frustration reactivity and regulation in a sample of adolescents who exhibited STO in childhood, and (2) test the putative contribution of dorsal anterior cingulate cortex (dACC) structure and functional connectivity assessed in childhood to these adolescent outcomes. This administrative supplement proposes a collaboration between the PI and researchers at the Child Mind Institute to expand this latter aim and address the issue of heterogeneity in children with STO by applying novel neuroanatomical subtyping analyses. The proposed study will use these methods to identify subgroups within the original sample of children with STO based on measures of cortical thickness, surface area, and complexity. Then, the validity of these subgroups will be assessed by examining how they differ from one another and from healthy comparisons on demographic, phenotypic, and functional connectivity measures. Functional connectivity will be examined using both targeted region-of-interest analyses of the dACC and connectome-wide association analyses. An additional aim is to assess the power of these neuroanatomical subgroups to predict adolescent outcomes, data that are currently being collected as part of the PI's R15. We will also test whether the neuroanatomical subgroups are better predictors of these adolescent outcomes than traditional DSM-5 categories. The final aim is to understand how these subgroups are differentially affected by underlying disease substrates, by performing data-driven whole-brain network simulation modeling allowing us to extract hidden information about pathological functional dynamics using resting state and diffusion weighted data. Fulfillment of study aims has the potential to advance our understanding of STO in childhood as a risk factor for adolescent pathology. Further, the addition of a bottom-up approach allows for the examination of multiple unknown pathways outside of the single target specified in the original application, allowing for the discovery of circuit disruptions that would represent novel hypotheses to test in a subsequent R01 proposal evaluating the associations between brain measures and psychopathological outcomes when these children are young adults.